[PATCH v2 4/5] dax: use sb_issue_zerout instead of calling dax_clear_sectors

Vishal Verma
2016-03-30T02:00:28Z

From: Matthew Wilcox <matthew.r.wilcox@intel.com>

dax_clear_sectors() cannot handle poisoned blocks. These must be
zeroed using the BIO interface instead. Convert ext2 and XFS to use
only sb_issue_zerout().

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
[vishal: Also remove the dax_clear_sectors function entirely]
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
fs/dax.c | 32 --------------------------------
fs/ext2/inode.c | 7 +++----
fs/xfs/xfs_bmap_util.c | 15 ++++-----------
include/linux/dax.h | 1 -
4 files changed, 7 insertions(+), 48 deletions(-)

diff --git a/fs/dax.c b/fs/dax.c
index ec6417b..f4ac5f2 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -78,38 +78,6 @@ struct page *read_dax_sector(struct block_device *bdev, sector_t n)
return page;
}

-/*
- * dax_clear_sectors() is called from within transaction context from XFS,
- * and hence this means the stack from this point must follow GFP_NOFS
- * semantics for all operations.
- */
-int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size)
-{
- struct blk_dax_ctl dax = {
- .sector = _sector,
- .size = _size,
- };
-
- might_sleep();
- do {
- long count, sz;
-
- count = dax_map_atomic(bdev, &dax);
- if (count < 0)
- return count;
- sz = min_t(long, count, SZ_128K);
- clear_pmem(dax.addr, sz);
- dax.size -= sz;
- dax.sector += sz / 512;
- dax_unmap_atomic(bdev, &dax);
- cond_resched();
- } while (dax.size);
-
- wmb_pmem();
- return 0;
-}
-EXPORT_SYMBOL_GPL(dax_clear_sectors);
-
/* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */
static void dax_new_buf(void __pmem *addr, unsigned size, unsigned first,
loff_t pos, loff_t end)
diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 6bd58e6..824f249 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -26,6 +26,7 @@
#include <linux/highuid.h>
#include <linux/pagemap.h>
#include <linux/dax.h>
+#include <linux/blkdev.h>
#include <linux/quotaops.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h>
@@ -737,10 +738,8 @@ static int ext2_get_blocks(struct inode *inode,
* so that it's not found by another thread before it's
* initialised
*/
- err = dax_clear_sectors(inode->i_sb->s_bdev,
- le32_to_cpu(chain[depth-1].key) <<
- (inode->i_blkbits - 9),
- 1 << inode->i_blkbits);
+ err = sb_issue_zeroout(inode->i_sb,
+ le32_to_cpu(chain[depth-1].key), 1, GFP_NOFS);
if (err) {
mutex_unlock(&ei->truncate_mutex);
goto cleanup;
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index a32c1dc..5b4351a 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -72,18 +72,11 @@ xfs_zero_extent(
struct xfs_mount *mp = ip->i_mount;
xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb);
sector_t block = XFS_BB_TO_FSBT(mp, sector);
- ssize_t size = XFS_FSB_TO_B(mp, count_fsb);
-
- if (IS_DAX(VFS_I(ip)))
- return dax_clear_sectors(xfs_find_bdev_for_inode(VFS_I(ip)),
- sector, size);
-
- /*
- * let the block layer decide on the fastest method of
- * implementing the zeroing.
- */
- return sb_issue_zeroout(mp->m_super, block, count_fsb, GFP_NOFS);

+ return blkdev_issue_zeroout(xfs_find_bdev_for_inode(VFS_I(ip)),
+ block << (mp->m_super->s_blocksize_bits - 9),
+ count_fsb << (mp->m_super->s_blocksize_bits - 9),
+ GFP_NOFS, true);
}

/*
diff --git a/include/linux/dax.h b/include/linux/dax.h
index 636dd59..933198a 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -7,7 +7,6 @@

ssize_t dax_do_io(struct kiocb *, struct inode *, struct iov_iter *, loff_t,
get_block_t, dio_iodone_t, int flags);
-int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size);
int dax_zero_page_range(struct inode *, loff_t from, unsigned len, get_block_t);
int dax_truncate_page(struct inode *, loff_t from, get_block_t);
int dax_fault(struct vm_area_struct *, struct vm_fault *, get_block_t,
--
2.5.5